1. Stem Cells and Cell Differentiation

2. Embryonic Stem Cells - Blastocyst Stage 3 parts: –Trophoblast –Blastocoel (“blastoseel”) or blastocyst cavity –Inner cell mass Millions of cells can come from one blastocyst http://www.kumc.edu/stemcell/images.html

3. 1. What are Stem Cells? a. Stem cells are different from all other cells in the body. b. Stem cells have 2 distinct properties: 1.They are unspecialized cells that are capable of renewing (regenerating) for long periods of time. 2.They can give rise to different types of somatic cells (specialized body cells).

4. Stem Cell Differentiation http://stemcells.nih.gov/info/basics/basics4.asp

5. 2. Types of Stem Cells a. Embryonic 1.Obtained from in vitro fertilization, or aborted embryos 2.3 or 4 day old embryo; blastocyst stage 3.Source of controversy

6. 2 types of Stem Cells a. Adult 1.Found among some differentiated cells in a specific tissue or organ; placental cord; baby teeth baby teeth

7. Adult Stem Cells Embryonic Stem Cells Aka Mature, somaticAka Early, blastocytic Come from developed body tissues, umbilical cord, placenta (after birth) Come from the inner cell mass of a blastocyst Multipotent - produces limited cell types Pluripotent - produces all cell types First isolated in 1960sFirst Isolated in 1998 Funding (1999-2004) $2.24 billion Funding (2002-2004) $55 million Results - over 50 therapeutic uses for humans Results - no human trials, some success with animal trials to date

8. 3. Unique Properties of Stem Cells a. Regeneration i.Stem cells can replicate themselves over longer periods of time than other body cells b. Differentiation i.Stem cells are unspecialized cells that can produce specialized body cells by first producing an intermediary cell http://www.kumc.edu/stemcell/images.html

9. 3. Unique Properties of Stem Cells ii. Stem cells differentiate by the activation of certain genes in DNA. iii. The genes that are activated determine the type of cell the stem cell will become.

10. 4. GENE REGULATION a. Virtually every cell in your body contains a complete set of genes b. But they are not all turned on in every tissue c. Each cell in your body expresses only a small subset of genes at any time d. During development different cells express different sets of genes in a precisely regulated fashion

11. GENE REGULATION e. Gene regulation occurs at the level of transcription or production of mRNA f. A given cell transcribes only a specific set of genes (exons) and not others (introns)

12. Pluripotent Differentiation http://www.kumc.edu/stemcell/images.html

13. http://www.stemcellresearch.org/testimony/20040929prentice.htmhttp://www.stemcellresearch.org/testimony/20040929prentice.htm Reprinted with permission of Do No Harm.

14. 4. How Do You Make Stem Cells? a. Fertilized Egg b. Isolate blastocyst c. Remove inner cell mass d. Place into petri dish coated with feeder cells to promote division e. Differentiation!

15. 5. Potential Uses of Stem Cell Research a. Cell based therapies: 1.Regenerative therapy to treat Parkinson’s, Alzheimer’s, ALS, spinal cord injury, stroke, severe burns, heart disease, diabetes, osteoarthritis, and rheumatoid arthritis 2.Stem cells in therapeutic cloning 3.Stem cells in cancer

16. 6. SCNT - Somatic Cell Nuclear Transfer a. Remove nucleus from egg cell and implant nucleus from patient’s cell to create fertilized egg. b. Remove inner cell mass from blastocyst and place in petri dish for stem cell development & differentiation c. Cells will be almost identical to patient so rejection will not occur when transplantated. http://www.kumc.edu/stemcell/early.htmlhttp://www.kumc.edu/stemcell/early.html Reprinted with permission from the University of Kansas Medical Center. 1. 2. 3.

17. 7. Cloning a. Reproductive Cloning 1.Producing new organisms genetically identical to donor b. Therapeutic Cloning 1.Make a therapeutic product (vaccine, human protein etc.) 2.Deliver organs that will not be rejected 3.Act as animal models for human disease c. Breeding animals or plants with genetically favorable traits (genetic engineering)

18. 6. Debate in US a. Federal funding available for research is strictly limited i.ES cell lines that were already in existence by 8/9/01 ii.Federal funding cannot be used on new embryonic stem cells b. Private companies continue to pursue stem cell research i.No federal funding

19. 7. Differentiation due to Environmental Factors a. Some cells differentiate due to environmental factors. b. Many disorders and diseases are the result of environmental differentiation i.Cancer ii.Fetal Alcohol Syndrome iii.Mesothelioma

20. References Stem cells & Cloning Stem cells & Cloning; David A. Prentice, Benjamin Cummings, 2003 http://www.pbs.org/wgbh/nova/sciencenow/3302/06.ht ml http://www.pbs.org/wgbh/nova/sciencenow/3302/06.ht ml http://www.stemcellresearch.org http://www.stemcells.nig.gov/info/nasics/nasics7.asp http://www.stemcells.nig.gov/info/scireport/2006report. htm http://www.stemcells.nig.gov/info/scireport/2006report. htm http://www.whitehouse.gov/news/releases/2001/08/20 010809-2.html http://www.whitehouse.gov/news/releases/2001/08/20 010809-2.html Stem cells in class; Badran, Shahira; Bunker Hill Community College, 2007, Boston Museum of Science Biotechnology Symposium Harvard Stem Cell Institute